fix(can): 캔 서비스 조회 트랜잭션을 적용한다

src/test/kotlin/kr/co/vividnext/sodalive/can/CanServiceTest.kt

@@ -10,6 +10,7 @@ import org.junit.jupiter.api.Test
 import org.mockito.Mockito.mock
 import org.mockito.Mockito.`when`
 import org.springframework.data.domain.PageRequest
+import org.springframework.transaction.annotation.Transactional
 import java.time.LocalDateTime
 
 class CanServiceTest {
@@ -134,6 +135,14 @@ class CanServiceTest {
         assertEquals("캐릭터 톡 이용권 구매", result[5].title)
     }
 
+    @Test
+    @DisplayName("캔 서비스 조회 로직은 read-only 트랜잭션 경계에서 실행된다")
+    fun `should run can service queries in read only transaction`() {
+        val transactional = CanService::class.java.getAnnotation(Transactional::class.java)
+
+        assertEquals(true, transactional.readOnly)
+    }
+
     private fun createUseCanDto(
         usage: CanUsage,
         can: Int,